Where is the speed sensor located on my 2003 Chevy Venture?

VJAKEHM

2003 CHEVROLET VENTURE

100,000 MILES

ABS waning light came on. It's likely that it's the spped sensor, but I have never changed one. Just wondering where it's located to work on it. It's a 30 dollar part, I don't want to spend $300.00 to have a mechanic do it.